• Journal of the Korea Computer Graphics Society
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• v.28 no.4
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• pp.13-22
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• 2022

In this paper, we propose a single framework based on the MPM(Material Point Method) that can represent the dynamic angular motion of the elementary particle unit. In this study, the particles can have various shapes while also describing linear and angular motion. As a result, unlike other particle-based simulations, which only represent linear movements of spherical (e.g. Circle, Sphere) particles, it is possible to express the visually dynamic motion of them. The proposed framework utilizes MPM, due to the fact that rotational motion can be decomposed and derived from large deformation. During the integration process of the presented technique, a deformation gradient tensor is decomposed by polar decomposition theory for extracting rotation tensor. By applying this together with the linear motion of each particle, as a result, it is possible to simultaneously express the angluar and linear motion of the particle itself. To verify the proposed method, we show the simulation of rotating particles scattering in the wind field, and the interaction(e.g. Collision) between a moving object and them by comparing the traditional MPM

• Communications of Mathematical Education
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• v.25 no.1
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• pp.63-78
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• 2011

The purpose of this study is to explore a teaching method of limits of functions with more intuitive and visual of CAS graphing calculators rather than with the rigorous ${\epsilon}-{\delta}$ method. Texas Instruments Voyage200 CAS graphing calculators are used for studying the possibility of the use of technology in calculus course. For this, various related theoretical constructs are reviewed: concept image, concept definition, cognitive conflict, the use of visualization of technology for calculus concepts, the theory of APOS, and local straightness. Based on such theoretical constructs this study suggests a teaching method of limits of functions with embodied visualization of CAS graphing calculators.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.83-93
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• 2013

By comparing Wiener's MMSE on stochastic signal transmission with Shannon's mutual information first proved by C.E. Shannon in terms of information theory, connections between two approaches were investigated. What Wiener wanted to see in signal transmission in noisy channel is to try to capture fundamental limits for signal quality in signal estimation. On the other hands, Shannon was interested in finding fundamental limits of signal quantity that maximize the uncertainty in mutual information using the entropy concept in noisy channel. First concern of this paper is to show that in deriving limits of Shannon's point to point fundamental channel capacity, Shannon's mutual information obtained by exploiting MMSE combiner and Wiener filter's MMSE are interelated by integro-differential equantion. Then, At the meeting point of Wiener's MMSE and Shannon's mutual information the upper bound of spectral efficiency and the lower bound of energy efficiency were computed. Choosing a proper lattice-type code of a mod-${\Lambda}$AWGN channel model and MMSE estimation of ${\alpha}$ confirmed to lead to the fundamental Shannon capacity limits.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.285-294
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• 2020

"The Man Standing Next" was a 'anger-character movie' that shows a fierce psychological game between the characters. Inspired by this point, it was analyzed the narrative structure of this film based on scene unit applying the 'Five-stage Anger Model' formulated by Lakoff and Kövecses and others. The results showed that the causality and feasibility of the protagonist's anger behavior were highly reflected above the model. In particular, among the five steps, the film-maker spent the longest time on 'anger control' justifying the hero's motivation for punishment or retaliation, while giving the shortest time to 'loss of control' to maximize the urgentness of the punitive actions. The detonator causing his anger at each stage was disposed two to six times each stage with neglect, contempt, arrogance, ostentation, mockery, unauthorized intervention, etc. Sneering of "Chief Security Officer" and insulting of "The President" make the protagonist feel the scorn of a terrible friend-murderer each functioned as a "rage trigger." In conclusion, the film follows the above sophisticated model in its narrative structure. Though it was a political drama that sets up a lot of anger scheme caused from public reasons, it reflects ordinary people's routine anger, which corresponds to 24 percent of the list of Nobaco's Provocation Inventory (PI). The producers elaborately reflected the anger procedure theory and balanced the public and private drivers of rage. It was considered to be derived from the intention to enhance communication with the audience increasing their understanding and aspiration for political movie that are usually heavy and unfamiliar.

• Journal of the Microelectronics and Packaging Society
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• v.23 no.4
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• pp.113-117
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• 2016

Recently, hydrogen is regarded as important energy in the future, because it is clean and renewable. The photoelectrochemical (PEC) system, which produce hydrogen using water splitting by solar energy, is one of the most promising energy systems because it has abundant energy sources and good theoretical efficiency. GaN has recently been regarded as suitable photoelectrode that could be used to split water to generate hydrogen without extra bias because its band edge position include water redox potential ($V_{redox}=1.23$ vs. SHE). GaN also shows considerable corrosion resistance in aqueous solutions and it is possible to control its properties, such as structure, band gap, and catalyst characteristics, in order to improve solar energy conversion efficiency. But, even if the band edge position of GaN make PEC reaction facilitate without bias, the overpotential of oxygen evolution reaction could reduce the efficiency of system. One of the ways to decrease overpotential is introduction of co-catalyst on photoelectrode. In this paper, we will investigate the effect of manganese dioxide ($MnO_2$) as a co-catalyst. $MnO_2$ particles were dispersed on GaN photoelectrode by spincoater and analyzed properties of the PEC system using potentiostat (PARSTAT4000). After coating $MnO_2$, the flat-band potential ($V_{fb}$) and the onset voltage ($V_{onset}$) were moved negatively by 0.195 V and 0.116 V, respectively. The photocurrent density increased on $MnO_2$ coated sample and time dependence was also improved. These results showed $MnO_2$ has an effect as a co-catalyst and it would enhance the efficiency of overall PEC system.

• Communications of Mathematical Education
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• v.34 no.3
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• pp.355-372
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• 2020

The concept of infinite series is an important subject of major mathematics curriculum in college. For several centuries it has provided learners not only counter-intuitive obstacles but also central role of analysis study. As the understanding in concept on infinite series became foundation of development of calculus in history of mathematics, it is essential to present students to study higher mathematics. Most students having concept of infinite sum have no difficulty in mathematical contents such as convergence test of infinite series. But they have difficulty in organizing concept of infinite series of partial sum. Thus, in this study we try to analyze construct the concept of infinite series in terms of APOS theory and genetic decomposition. By checking to construct concept of infinite series, we try to get an useful educational implication on teaching of infinite series.

• Bulletin of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.57-63
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• 1995

극지개발을 위해서는 극지의 혹독한 자연환경을 대상으로 하는 과학지식과 극지에서 사용되는 특수시설과 장비를 설계, 시공 그리고 운용하는 공학기술이 요구된다. 극지관련 공학기술은 저 온용재료 관련기술, 도로나 교량, 건축물과 같은 극한지 천연자원의 시추와 생산, 수송을 위한 해양구조물과 파이프라인 관련기술, 그리고 얼음의 재료특성에 관한 이론 및 실험으로 크게 구 분할 수 있다. (Table 1). 극지용 구조물과 빙해항행선박 (쇄빙선) 은 일반 해역에서 운용되는 구조물에 비해 형상, 구조강도, 의장, 저온특수설비 등에서 새로운 개념의 기술이 요구되기 때 문에 금후 국내 조선해양산업계가 지향해야 할 고도의 기술집약형 건조물이다. 또한 최근 들어 국내에서도 시베리아 천연자원의 해상운송을 위해 빙해역을 운항할 수 있는 유조선이나 일반 화물선을 확보해야할 필요성이 대두되고 있으며, 또한 국내 조선업계의 생산기술이 비약적으로 발전함에 따라 외국으로부터의 빙해항행선박의 수주도 이루어지고 있으나 아직 이들 선박의 설계를 위한 독자적인 기술은 미흡한 현실이다. 극지개발은 이론적 접근과 함께 실험에 의한 신뢰성 있는 자료를 축적해야 한다. 이를 위해서는 빙해수조(,ice model basin)의 건조나 빙역학 실험을 위한 냉동실험실 (cold room)의 건립을 위한 초기투자가 절실히 요구되며 산업계의 수 요에 따른 포괄적인 산학협동연구가 진행되어야 할 필요가 있다. 빙해수조와 냉동실험실은 빙 해역에 직접 접하지 않은 국가에서 극지공학 연구에 참여하기 위한 필수적인 시설인데 table 2에 대표적인 빙해수조의 설치장소와 규모에 대하여 정리하였다. 이 글은 우리 나라가 쉽게 접할 수 없는 극지환경을 이해하고 가까운 장래에 예상되는 수주경쟁에 대비하여, 국내외의 극지개발 동향을 분석하고 이에 대한 국내의 극지관련 연구의 현황과 앞으로의 전망을 살펴보기 위하여 준비된 것이다. 이 글에서는 극지공학 일반보다는 조선해양분야에 관련된 내용만으로 국한한다.

• Journal of the Korean Society of Costume
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• v.33
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• pp.143-156
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• 1997

와관과 실체의 갈등은 문학작품의 주제 중에서 가장 보편적이면서도 복잡한 양상을 지니고 있다 희곡 Macbeth에 있어서 이주제는 Shakespeare의 어느 작품에서보다도 핵심적인 역할을 하며 특히 외관과 실체의 주제를 시각적으로 보여주는 복식이미저리는 그의 주제를 상징적으로 나타내는 데 효과적일 뿐만 아니라 극적 분위기 창조 및 무대사에서배우들의 의상변화로 인한 시각적이미저리 효과를 극대화 시키고 있다 본 연구의 목적은 Macbeth에 내재된 복식 이미저리를 고찰하고 이를 가장 최근에 공연된 macbeth의 무대의상에 적용 분석함으로써 무대의상 제작시 복식 이미저리의 효과적인 무대적용 여부를 파악하는 것이다.연구의 방법은 먼저 이론적인 배경으로 희곡 Macbeth의 본문을 분석하여 복식이미지저리와 관계된느 대사 및 지문 등을 추출한 다음이를 하나의 케이스 연구대상으로 선정된 1996 RSC극단 공연의 Macbeth 무대의상에 적용하여 분석 고찰 하였다 본 연구에서 얻어진 결론은 다음과 같다 첫째 자신의 실체를 파악하지 못한 인물이나 혼동하는 인물은 자신의 신분에 맞지 않은 남의 의상을 적응기간조차 없이 착용함으로써 결국은 자신을 파멸로 몰고가는 복식 이미저리가 제시되어 있었다 둘째 자신의 실체를 분명히 지각하고 있는 인물들은 새로운 복식이나 신분에의 적응은 많은 시간과 노력을 요한다는 것을 매우 잘 파악하고 있었으며 이것은 그들의 대사 중에 구체적으로 제시되어있었다 1막1장의 Banquo 의 대사 중에 나오는'새로운복식'과 '새로운 신분'에 비유 2막 4장의 macduff의 대사중에 나오는 '새로브'와 '헌로브'의 비유 5막 2장의 Caithness의 '자제력의혁대'등의 비유는 복식이미저리의 구체적인 표현으로 분석되었다. 셋째 복식 이미저리의 측면에 1996 RSC의 Macbeth 무대의상을 분한 결과 이의상들에는 '난쟁이가 훔쳐 입은 거인의 옷' 으로 대표되는 복식 이미저리가 직접적으로 제시되지는 않았지만 공연전체를 통하여 무대장치 및 의상에 변화를 주지 않음으로써 이 작품의 초시한성과 복식이미저리를 오히려 역설적으로 표현하고 있는 것으로 파악되었다. 따라서 이공연의 의상 계획은 복식 이미저리의 역설적인 한 표현으로 분석되었으며 관객에게 등장인물의 외곤은 그 실체를 그대로 반영한다는 Shakespeare 본래의 의도를 잘 보여주는 의상계획으로 파악되었다 이러한 결과는 Shakespeare극의 무대의상 디자인 및 제작시 무대의상이 단순한 무대의상 그 이상의 의미로 고려되어져야 함을 보여주며 이는 관객에세 의미 깊은 메시지로 전달될 수 있을 것으로 사료된다.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.5
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• pp.187-195
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• 2005

A new segmentation-based image coding method which no needs transmission of contour data is proposed. The shape information acts as bottleneck in the segmentation-based video coding because it has much portion of transmission data. The proposed method segments a previous decoded frame, instead of a current frame. As a result, there is no need for transmission of contour information to a decoder. Therefore, the saved bits can be assigned to encode other information such as error signals. As shown in experiment results, if data rate is very highly increased due to abrupt motion under very low bit rate coding having limited transmission bits, PSNR of conventional block-based method go down about 20dB, while the proposed method shows a good reconstruction quality without rapid PSNR drop.